Intercooler and plumbing (Ebay brand). Nicely packaged and it all seems to work:

Intercooler mock-up. I wanted to run the in/out tubes beneath the headlights to make plumbing as simple (and straight) as possible. The 2.5” tube is very tight between the frame and headlight buckets.

Had to notch some of the lower rad-support for clearance. None of the frame rails were modified. I also cut out a bit of the valence to increase airflow to the upper parts of the IC.

Intercooler and oil cooler mounted. I used a simple 3/4” square tube for support. The oil cooler is also mounted to tabs on this tube. The IC is supported at the bottom by small tabs welded to the chassis.

TPS and IAT. The TPS is the typical unit from the E36 and others. Part number: 13 63 1 726 591
The IAT is a standard GM unit, bought from DIYautotune. I wanted to mount the IAT as close as possible to the engine, without having to deal with welding into the charge piping. This was an obvious solution. Drill + tap (and also machined it down a bit):